Apparatus for regulating combustion in furnaces.



J. F. GANADY.

APPARATUS FOR REGULATING comsusnom IN FURNACES.

APPLICATION FILED SEPT. 21, 1909.

Patented. July 7, 1914.

2 SHEETS-S11E51 1.

I. F. QALIADY.

FOR RBGULATING COMBUSTION IN PURmcEs.

APIARVEE.

APPLICATION FILED SEPT. 21, 1909.

Pafwnted 7, 19143 2 SHEBTSSHEET 2.

amut tron Gum/neg:

areas-rs.

JQSEPH If. CANY, 01E JEY CIT-Y, NEW SEY.

,r TUS FGR REGULATING COMBUSTIDN IN FUNACES.

Specification of Eetters'fatent,

Patented duty "3, 1214a Application filed September 21, 1 Serial No.518,819;

' that type wherein the pressure in the comously arranged bustionchamber is maintained substantially constant and wherein any variationof pressure in the. combustion chamber acts upon a regulating mechanism,which automatically operates to restore the conditions within thefurnace to normal.

In furnace regulating devices as heretofore constructed, the steamressure has been utilized to control both t e escape of the products ofcombustion to the stack and the admission of the air from a suitableforced-draft mechanism. The pressure in the combustion .chamber istherefore controlled indirectly by the steam pressure and it is possible'to obtain quite a wide variance in pressure as compared to the airpressure in the boiler room.

Inmy present invention the air supply to the combustion chamber iscontrolled directly by the pressure in said chamber and therefore anyvariation which may occur in- 'stantly affects the apparatus and eitheroperates to reduce the pressure to normal or raise the same, as the casemay be. Furthermore, by my novel construction the steam pressure above afixed maximum is utilized to operate an auxiliary control mechanism,whereby the pressure in the combustion chamber is further regulated andacts upon the regulating apparatus, which is influenced thereby, to cut.ofi or open the damper-controlling the air supply.

For the purpose of illustrating my invention, I have shown in theaccompanying drawin s oneform thereof which is at resent re erred by me,since the same-has een found. in practice to give satisfactory andreliable'results, although it is to be understood that the variousinstrumentalities of.

which my invention consists can be vanand organized and that myinvention isnot limited to the precise arrangement and organization ofthese instrumentalities" as herein shown and described.

to an arm a diaphragm chamber 21, wherein it is Figured presents a sideelevation. of a steam boiler provided. with an apparatus embodying myinvention. Fig. 2 represents a -sectlon through one portion or mycontrol" apparatus. Fig. 3 represents an end elevatlOIl of the same.Fig. 4 represents a side elevation of the same. Fig. 5 represents asection through another portion of my control apparatus.

Similar numerals of reference indicate corresponding parts in thefigures.

Referring to the drawings :--1 designates an ordinary type of boilerfurnace, comprismg a com ustion chamber 2, ash pit 3 and stack outlet 4of any well known construction and forming no specifi portion of mypresent invention.

5 designates a damper pivoted in any suitable manner on the stack 4,whereby the passage of the products of combustion from the furnace tothe stack may be controlled as desired. In the present instance a lever6 is secured to the damper 5 and has mounted thereon a weight 7 for thepurpose of swinging the damper 5 in one direction while in the otherdirection it is operated by means of a rope 8 or equivalent means,

which, as here shown, is controlled by an automatic controlling device9. .In the present instance this device is adapted to be actua'ted bythe steam pressure in the boiler and consists of a connecting rod 10 towhich is secured the lever operating means 8, the said rope passingthrough the usual stufling box structure to the interiorof the cylinder11, wherein it terminates .in a piston 12, against which the operatingpressure is a apted to actuate and reciprocate the rod 10 in therequired manner.

Ports 13 and 14 communicate respectively with opposite ends of thecylinder 11 in order toadmit pressure alternately to each side of thepiston 12 and they also communicate with chamberv 15 having therein aslide valve mechanism 16 which is connected .byla rod 17 to an operatinglever 18 suita y mounted on the casing 15. As here shown, the lever 18is connected by a rod 19 20, one end of which extends into mounted bymeans of knife edge constructions 22 and 23, whereby a pivot action ispermitted, the movement of the bar, 20 being controlled in one directionby a pressure diaphragm 24 and in the opposite direction by acounterweight 25. Pressure is admittedbeneaththe diaphragm 24 by meansof a port 26 to which it is led by means of a pipe 27, preferablyconnected tothe steam outlet 28 of the boiler, although of course it maybe led from any suitable portion of the steam head.

It. will be apparent that by suitable adjustment of the counterweight 25substantially any desired pressure may be exerted-upon the diaphragm 24which must be overcome by the steam pressure before the arm 20 will beraised and it will be seen that when the pressure in the boiler exceedsthe pressure on the opposite side of the diaphragm 24, as determined bythe counterweights 25, that the lever 20 will be raised and consequentlyshift the valve 16 so as to admit a suitable fluid pressure through theinlet 29 and by way of valve 16 to the port 13, whereupon the piston 12is shifted to move the arm 10 to the right, as shown in Fig. 5. Ofcourse it will be understood that when this connection is effected theport 14 will be thrown into communication with the exhaust port 31 ofthe chamber 15. This movement of the rod 10 pulls upon the connectingrope 8, whereupon the Weight 7 is raised and the damper 5 closed so thatthe products of combustion cannot escape to the stack 4. Should,however, the pressure in the boiler now drop below that exerted on thediaphragm 24 by the arm 20, the rod 18 will be correspondingly loweredand the valve 16 brings the port 14 into communication with the inlet 29and the port 13 in communication with the exhaust 31, whereby the piston12 is shifted to the other end of the cylinder 11 and the connecting rod10 forced to the left, as shown in Fig. 5,

thus allowing the counterweight 7 to lower and open. the damper 5.

The closing of the damper during the operation of the furnace will ofcourse result in a raising of the pressure of the products of combustionin the combustion chamber, of which I take advantage and introduce apressure control mechanism by which air passing through the burning fuelis accurately controlled, In the present instance this pressurecontrolapparatus consists of a casing 32 secured at a suitable point tothe boiler 1 and having an opening 33 in ali 'ement with an aperture 34communicatingwith the combustion chamber. The casing 32' is provided.with air fpassages 35 leading to the interior thereo between which andthe opening 33 is suspended a plate 36 closely conforming to theinterior of the casing 32 in order to prevent substantially any airpassing through to the combustion chamber but at the same timepermitting a free movement of the plate 36. As here shown, the plate 36is secured at one end to a rod 37 passingthrough suitable bearings inthe casing 32, whereby the plate 36 is pivoted and may swing freelywithin the casing 32 Itwill be apparent if the pressure within thecombustion chamber exceeds the atmospheric pressure that the plate 36will take the position indicated in dotted lines in Fig. 2 and while insuch position hold a rock bar 38 in position 'to operate partshereinafter to be described. Should, however, the pressure in thecombustion chamber dro below atmospheric pressure the plate 36 wi 1swing and assume a position in full lines, Fig. 2, whereupon the rod 38connected thereto will be shifted to its opposite operative position.

39 designates a valve casing suitably supported on the boiler 1 and inclose proximlty to the rod 38, which latter has secured thereto at oneend, a valve operating rod 40 passing into the casing 39, having mounted.valve chamber 39 and having therein a connecting rod 46 which isconnected to theopposite end of the rod 38, whereby a dash pot structureis formed adapted to cooperate v with the movement of the plate'36 toshift the valve rod 40 in one direction.

47 designates a cylinder suitably supported ad acent the casing 32 andhaving a I pipe 48 communicating with the interior thereof at one endand connected to the inlet port 42, whereby fluid pressure may beadmitted to the cylinder 47 and actuate a piston 49 secured to a rod 50passingthrough a suitable stuffing box in the end of the cylinder 47 andconnected to a rope 51 or like operating means, secured to a damper 52controlling the admission of air to the ash pit 3. V

53 designates an exhaust pipe leading from the cylinder 47 in order torelieve the pressure therein and permit the piston 49 to return to itsnormal position after its operation. It will be clear that if the rod 38is operated by the plate 36 so as to bring the ports 42 and 44 intocommunication,-

that fluid pressure will be transmitted beneath the piston 49 in thecylinder 47 and raise the same, whereby the damper 52 is closed, andprevents a flow of air through the passage 54. This movement takes placewhenever the pressure in the combustion chamber is above that of theoutside atmosphere and it is desired to prevent any further air beingoperated to promote combustion in the chamber 2. As soon, however, asthe pressure in the combustion chamber 2 drops, the plate 36 swingsagain so as to move the rod 38 to shift the valve 41 so as to throw theports 43 and 44 into communication, whereby the pressure beneath thepiston 49 is relieved and the counterweight on the damper regulating rod51 returns the parts and opens the damper 52.

The operation of the device is as follows :-.-In operation the automaticdamper regulator is adjusted to the required pressure by means of thecounterweight 25 and the damper set in open position to be controlled bythe regulator, as required. Air is supplied from ablower or othersuitable means to the passage 54:, the damper 52 of course being open topermit the air to pass into the ash pit and promote combustion in thechamber 2. The pressure in the combustion chamber 2 is at this timesubstantially the same as that of the atmosphere or the pressure of theboiler room and the plate 36 is therefore hanging as indicated in fulllines in Fig. 2 so as to maintain the valves controlling the chamber 52in normal position, that is with the damper 52 open. As the steampressure rises a pressure is sooner or later reached at which the actionof the counterweight 25 is overcome and the bar 20 through the upwardmovement of the diaphragm 24 is raised to shift lever 18 and actuate thevalve 16 to admit pressure to the cylinder 11. As soon as this takesplace the damper 5 is actuated as before described and swings to closedposition. Of course the closing of this damper has the effect of chokingback the products of combustion which are still being added to by airforced through the passage 54L and soon a pressure is reached greaterthan the atmospheric pressure and the plate 86 is moved to the positionindicated in dotted lines Fig. 2 and thereby brings the valve structure39 into operation and admits pressure to the cylinder 47, whereupon theair damper 52 is dropped and the supply of air out off. This action cutsoff the supply of air to the combustion chamber and the pressure islowered, whereby the plate 36 swings back to normal position, opening upthe air supply and as the steam pressure has in the meantime dropped theautomatic damper control also comes into operation and opens the damperto the stack l. 1 g It will now be apparent that I have devised a novelconstruction of a furnace regulator whereby the pressure in thecombustion chamber operates directly to control the air supplied theretoand wherein a pivoted member maintained in normal position by gravityand subjected to the pressure of the combustion chamber on one side andon the other to the constant pressure of the atmosphere comprises a partof the complete unitary structure producing the result desired.

In so far as I am aware I am the first in the art to employ in a deviceof the character hereinbefore described, a controlling device governedby the steam pressure of the boiler and operating to cause a variationin the pressure, existing in the combustion chamber, whereby a secondaryapparatus consisting of a pivot member, operates directly to control thesupply of air promoting combustion.

It will now be apparent thatIhave devised a novel and usefulconstruction which embodies the features of advantage enumerated asdesirable in the statement of the invention and the above descriptionand while I have in the present instance shown and described thepreferred embodiment thereof which has been found in practice togivesatisfactory and reliable results, it is to be understood that the sameis susceptible of modification in various particulars without departingfrom the spirit or scope of the invention or. sacrificing any of itsadvantages.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is

The combination with a boiler and its furnace, of means for supplyingair under pressure to the furnace, means controlled by the boilerpressure for regulating the discharge from the furnace of the productsof combustion, and means controlled by the variations in furnacepressure for control ling the admission to the furnace of air from theair-supplying means in correspondence with the variations in thedischarge of the products of combustion.

J OSEPH F. CANADY.

Witnesses:

ESTELLE LEVY,

